摘要:
The invention relates to a method for the continuous lambda control of an internal combustion engine 13 having a catalyzer. The method is carried out by generating a control oscillation FS of pregiven amplitude at least in pregiven operating conditions. This method is based on the recognition that with an increase in amplitude of the control oscillation, the conversion window becomes wider insofar as a maximum amplitude is not exceeded. The conversion window is that range of lambda values wherein the conversion exhibits at least a pregiven quality.
摘要:
The invention is directed to a method for controlling the composition of the air/fuel mixture for an internal combustion engine. In the method, the mean value of the control oscillation is influenced via a change of the delay times tv with which a sign reversal of the actuating variable change is delayed. The dead time of the control is determined from the time-dependent performance of the control actuating variable and is considered for the change of the delay times tv.
摘要:
The invention is directed to a method for reducing the exhaust-gas emissions of an internal combustion engine which is equipped with a lambda control and a catalytic converter and for which the metering of fuel can be interrupted in dependence upon operating parameters. The method is characterized in that the engine at first is operated with a rich fuel/air mixture during transition from operation without fuel metering to operation with fuel metering. The oxygen deficiency associated therewith compensates the oxygen excess which is stored in the catalytic converter when the metering of fuel is interrupted. An operating state wherein oxygen is loaded therefore occurs quickly after a fuel cutoff. This operating state also defines an optimum at steady state and this is advantageous especially for the conversion of nitrogen oxide.
摘要:
A mixture controller for adjusting an output value, which is outputted by a PI two-point controller, to control the air/fuel ratio of a mixture supplied to an internal combustion engine to a pregiven value. The engine produces an exhaust-gas flow during operation and has an oxygen probe mounted in the exhaust-gas flow. The mixture controller continuously detects the signal of the oxygen probe to obtain sequential measurement values of the signal. A check is made as to whether a currently detected measurement value of the signal has crossed over a threshold value in the lean or rich direction compared to the previously detected measurement value of the signal. The output value is changed when a crossover of the signal in the lean direction is present by shifting the output value with a large step via a P-jump in the rich direction and starting an integration of the output value in the rich direction from a previous lean direction. The output value is also changed when a crossover of the signal in the rich direction is present by stopping the integration of the output value in the rich direction and starting an integration in the lean direction after a pregiven delay time has elapsed. The operation of the mixture controller is returned to checking after the output value has changed. A return of the operation of the mixture controller to the checking operation is inhibited until an inhibit time has elapsed.
摘要:
The invention is directed to a method for determining the particular current value of at least one control parameter for a lambda control of an internal combustion engine which provides a shift to make the fuel mixture lean or a shift to make the fuel mixture rich in dependence upon the operating state of the controlled engine. The method includes the steps of: determining a base value for the control parameter in dependence upon the current value of at least one pregiven operating variable as the current value applies for a control with a minimal discharge of toxic gas during steady-state operation of the engine; and, modifying the base value with a transition variable having a value decaying as a function of time when changes in the operating state of the engine occur. The method of the invention affords the advantage that the control parameter does not have a value which was applied for a minimum discharge of toxic gas for a typical operation sequence at steady-state or transient operation; instead, for steady-state and transient operations, optimized values are available. In this way, a discharge of exhaust gas is obtained which is lower compared to possibilities which have existed up until now.
摘要:
A method and an electronic circuit for regenerating an electrical contact are provided in order to remedy the problem of electrical contacts becoming highly resistive over time. Electrical contacts become highly resistive over time, particularly when the contacts are thermally highly stressed and/or exposed to corrosive gases. To remedy this undesired effect and to reestablish the low resistance of the contacts, an electrical regenerating signal is applied to these contacts.
摘要:
The internal resistance of a lambda probe is determined by: the application of a clocked direct-current counter voltage to the probe via a series resistor; the measurement of the output voltages with the counter voltage connected and disconnected; and, the calculation of the internal resistance from the measured values and known resistance values.Apart from the components of a conventional arrangement, this method requires only a series resistor and a switch for implementation. Measurement can be carried out at short time intervals without excessively high direct-current voltage loading which affects the service life.The internal resistance measured is compared with a desired resistance and the control deviation determined in this way is used to determine the duty factor for probe heating clocked with fixed frequency.
摘要:
An arrangement for lambda control operates on an internal combustion engine (11) comprising a catalytic converter (12) and a lambda probe (13.v) mounted in front of the catalytic converter and a lambda probe (13.h) mounted behind the catalytic converter. The arrangement integrates by means of an integration means (15) the difference between the actual lambda value measured by the rear probe and the lambda desired value to which controlling is to be effected. The integration value is used as control desired value for a means (16) for lambda control. This arrangement and the associated method make it possible to control to the actually wanted lambda desired value even if the front lambda probe carries out incorrect measurements, for example because of hydrocarbons in the exhaust gas in front of the catalytic converter or, in the case of continuous-action control, faulty linearization of the probe characteristic.
摘要:
A control system for controlling the air/fuel ratio in an internal combustion engine 10, in which an oxygen probe (lambda probe) 13 is arranged in the exhaust gas of the internal combustion engine 10, has a control device 12 for continuous control. The actual value of the air ratio lambda is determined via a measured probe output voltage in conjunction with an at least approximately predetermined probe-characteristic relationship 16 between the value of the probe output voltage and the value of the air ratio lambda associated therewith. After forming the difference of desired value and actual value of the air ratio lambda, the air/fuel ratio is controlled on the basis of this difference. Such a control system is used primarily in order to reduce the total emission of the main pollutant components of the exhaust gas of an internal combustion engine. In particular in the case of an internal combustion engine 10 with catalytic converter arranged in the exhaust gas, a maintenance of the air ratio lambda as accurate as possible necessary for optimum efficiency of the catalytic converter (lambda=1) is assured.
摘要:
A method and an electronic circuit for regenerating an electrical contact are provided in order to remedy the problem of electrical contacts becoming highly resistive over time. Electrical contacts become highly resistive over time, particularly when the contacts are thermally highly stressed and/or exposed to corrosive gases. To remedy this undesired effect and to reestablish the low resistance of the contacts, an electrical regenerating signal is applied to these contacts.